1. Field of the Invention
The present invention relates generally to dielectric films formed from siloxane based resins and methods of manufacturing those films, and more specifically to low dielectric constant films formed from high organic content organohydridosiloxane compositions and methods of manufacture thereof.
2. Related Art
Semiconductor devices often have one or more arrays of patterned interconnect levels that serve to electrically couple the individual circuit elements thus forming an integrated circuit (IC). These interconnect levels are typically separated by an insulating or dielectric film. Previously, a silicon oxide film formed using chemical vapor deposition (CVD) or plasma enhanced CVD (PECVD) techniques was the most commonly used material for such dielectric films. However, as the size of circuit elements and the spaces between such elements decreases, the relatively high dielectric constant of such silicon oxide films is problematic.
In order to provide a lower dielectric constant than that of silicon oxide, dielectric films formed from siloxane based resins are becoming widely used. One such family of films formed from siloxane based resins are the films derived from hydrogen silsesquioxane (HSQ) resins (See, U.S. Pat. No. 3,615,272, Oct. 19, 1971, Collins et al.; and U.S. Pat. No. 4,756,977, Jul. 12, 1988, Haluska et al.) However, while such films do provide lower dielectric constants than CVD or PECVD silicon oxide films and also provide other benefits such as enhanced gap filling and surface planarization, it has been found that typically the dielectric constants of such films are limited to approximately 3.0 or greater (See, U.S. Pat. No. 5,523,163, Jun. 4, 1996, Ballance et al.).
Since, as known, the dielectric constant of such insulating films is an important factor where IC's with low power consumption, cross-talk, and signal delay are required, forming an insulating film with a dielectric constant below 3.0 is desirable. As siloxane based resin materials have beneficial gap filling and planarization properties, forming such films from siloxane based resin materials is very desirable. In addition, it would be desirable to have low dielectric constant films formed from siloxane based resin materials which have a high resistance to cracking. Additionally, it would be desirable to manufacture low dielectric constant films from siloxane based resins via standard processing techniques. In this manner curing processes that require an ammonia or ammonia derivative type of atmosphere (See, U.S. Pat. No. 5,145,723, Sep. 8, 1992, Ballance et al.), an ozone atmosphere (See, U.S. Pat. No. 5,336,532, Haluska et al.), or other non-standard type of semiconductor process, are avoided.